X

: /js/ (e.g. laisser from laxare)

French

: /ss/ (e.g. asse from axem) and, in some cases, /ʃʃ/ (e.g. lasciare from laxare)

Italian

: /jʃ/ (e.g. eixo from axem)

Portuguese

: /ps/ (e.g. coapsă from coxa) and /s/ (e.g. lăsa from laxare)

Romanian

Old Spanish

Spanish

In , ⟨x⟩ has three pronunciations; the most common is /ʃ/; as in 'xarop' (syrup). Others are: /ks/; 'fixar' (to fix), /ɡz/; 'examen'. In addition, /ʃ/ gets voiced to [ʒ] before voiced consonants; 'caixmir'. Catalan also has the digraph ⟨tx⟩, pronounced /tʃ/.

Catalan

In and Leonese, ⟨x⟩ is pronounced /ʃ/ in most cases (often used in place of etymological g or j). The pronunciation /ks/ occurs in learned words, such as 'taxativo' (taxing). However, Galician speakers tend to pronounce it /s/, especially when it appears before plosives, such as in 'externo' (external).

Galician

In , ⟨x⟩ usually represents /ks/ or (primarily in words beginning with ex- followed by a vowel) /ɡz/. It is pronounced /s/ in some city names such as Bruxelles (although some people pronounce it 'ks') or Auxerre; it is nevertheless pronounced /ks/ in Aix, the name of several towns. At the ends of other words, it is silent (or /z/ in liaison if the next word starts with a vowel). Two exceptions are pronounced /s/: six ("six"), dix ("ten"). It is pronounced /z/ in sixième and dixième.

French

In , ⟨x⟩ is either pronounced /ks/, as in extra, uxorio, xilofono,^[5] or /ɡz/, as exogamia, when it is preceded by ⟨e⟩ and followed by a vowel. In several related languages, notably Venetian, it represents the voiced sibilant /z/. It is also used, mainly amongst the young people, as a short written form for "per", meaning "for": for example, "x sempre" ("forever"). This is because in Italian the multiplication sign (similar to ⟨x⟩) is called "per". However, ⟨x⟩ is found only in loanwords, as it is not part of the standard Italian alphabet; in most words with ⟨x⟩, this letter may be replaced with 's' or 'ss' (with different pronunciation: xilofono/silofono, taxi/tassì) or, rarely, by 'cs' (with the same pronunciation: claxon/clacson).

Italian

In , ⟨x⟩ has four main pronunciations; the most common is /ʃ/, as in 'xícara' (cup). The other sounds are: /ks/ as in 'flexão' (flexion); /s/, when preceded by E and followed by a consonant, as in 'contexto' (/ʃ/ in European Portuguese), and in a small number of other words, such as 'próximo' (close/next); and (the rarest) /z/, which occurs in the prefix 'ex-' before a vowel, as in 'exagerado' (exaggerated). A rare fifth sound is /ɡz/, coexisting with /z/ and /ks/ as acceptable pronunciations in exantema and in words with the Greek prefix 'hexa-'.

Portuguese

In and Ligurian, ⟨x⟩ represents /ʒ/.

Sardinian

In , ⟨x⟩ was pronounced /ʃ/, as it is still currently in other Iberian Romance languages. Later, the sound evolved to a /x/ sound. In modern Spanish, due to a spelling reform, whenever ⟨x⟩ is used for the /x/ sound it has been replaced with ⟨j⟩, including in words that originally had ⟨x⟩ such as ejemplo or ejercicio, though ⟨x⟩ is still retained for some names (notably 'México', even though 'Méjico' may sometimes be used in Spain). Presently, ⟨x⟩ represents the sound /s/ (word-initially), or the consonant cluster /ks/ (e.g. oxígeno, examen). Rarely, it can be pronounced /ʃ/ as in Old Spanish in some proper nouns such as 'Raxel' (a variant of Rachel) and Uxmal.

Old Spanish

In , ⟨x⟩ represents the voiced alveolar sibilant /z/ much like in Portuguese 'exagerado', English 'xylophone' or in the French 'sixième'. Examples from medieval texts include raxon (reason), prexon (prison), dexerto (desert), chaxa or caxa (home). Nowadays, the best-known word is xe (is/are). The most notable exception to this rule is the name Venexia /veˈnɛsja/ in which ⟨x⟩ has evolved from the initial voiced sibilant /z/ to the present day voiceless sibilant /s/.

Venetian

The X represents the number 10.^[6][7]

Roman numeral

In , x is commonly used as the name for an independent variable or unknown value. The modern tradition of using x, y and z to represent an unknown (incognita) was introduced by René Descartes in La Géométrie (1637).^[8] As a result of its use in algebra, X is often used to represent unknowns in other circumstances (e.g. X-rays, Generation X, The X-Files, and The Man from Planet X; see also Malcolm X).

mathematics

On some identification documents, the letter X represents a , where F means female and M means male.^[9][10]

non-binary gender

In the , x is used to refer to the horizontal axis.

Cartesian coordinate system

It is also sometimes used as a for the multiplication sign, ×. In mathematical typesetting, x meaning an algebraic variable is normally in italic type (${\displaystyle x\!}$), partly to avoid confusion with the multiplication symbol. In fonts containing both x (the letter) and × (the multiplication sign), the two glyphs are dissimilar.

typographic approximation

It can be used as an abbreviation for 'between' in the context of historical dating; e.g., '1483 x 1485'.

Maps and other images sometimes use an X to label a specific location, leading to the expression "X marks the spot".

[11]

In art or fashion, the use of X indicates a collaboration by two or more artists, e.g. Aaron Koblin x Takashi Kawashima. This application, which originated in Japan, now extends to other kinds of collaboration outside the art world. This usage mimics the use of a similar mark in denoting botanical hybrids, for which scientifically the multiplication × is used, but informally a lowercase "x" is also used.

[12]

At the end of a letter or other correspondence, '' can mean a kiss;^[13] the earliest example of this usage cited by the Oxford English Dictionary is from 1878.^[14]

x

An denotes media such as movies that are intended for adults only.

X rating

In the , a series of Xs is used as a visual bleep censor for subtitles and captions, serving the same role as an asterisk (*).^[15][16]

Korean language

In the , "x" preceded by zero (as in 0x or 0X) is used to denote hexadecimal literal values.

C programming language

X is commonly used as a prefix term in nouns related to the X Window System and Unix.

[2]

X with : Ẍ ẍ Ẋ ẋ X̂ x̂ ᶍ^[17]

diacritics

-specific symbols related to X: χ

IPA

Teuthonista

[18]

 : Modifier letter small x is used for phonetic transcription

ˣ

ₓ : Subscript small x is used in ^[19]

Indo-European studies

X mark

Media related to X at Wikimedia Commons

The dictionary definition of X at Wiktionary

The dictionary definition of x at Wiktionary

. The American Cyclopædia. 1879.

"X"